Thread break detector

ABSTRACT

Thread being wound is passed through a tensioning device which includes a fixed member and a movable member which is urged towards the fixed member to tension the thread therebetween. A permanent magnet is attached to the movable member. A reed switch is positioned so that it is actuated when the magnet moves to within a predetermined distance therefrom, this proximate actuation position being attained when the thread breaks and the movable member moves in response to the tensioning force applied thereto. The switch operates to actuate a suitable control device which may operate a warning indicator and/or stop the threadwinding operation.

United States Patent Primary Examiner-Leonard D. Christian Attorneys-Sukolski and Wohlgemuth and W. M. Graham ABSTRACT: Thread being wound is passed through a tensioning device which includes a fixed member and a movable member which is urged towards the fixed member to tension the thread therebetween. A permanent magnet is attached to the movable member. A reed switch is positioned so that it is actuated when the magnet moves to within-a predetermined distance therefrom, this proximate actuation position being attained when the thread breaks and the movable member moves in response to the tensioning force applied thereto. The switch operates to actuate a suitable control device which may operate a warning indicator and/or stop the thread-winding operation.

PATENTEU FEB 9 IHYI THRE A D WINDING MACH/NE FIG.

INDICATOR CONTROL DE VICE POWER SOURCE INVFNTOR BERT B. MORGAN SOKOLSK/ 8 WOHLGEMU TH THREAD BREAK DETECTOR This invention relates to thread winding, and more particularly to a device for detectinga break in thread being wound on a thread-winding machine or the like and providing a control signal to enable the correction of such situation.

In the winding of thread on an automatic thread-winding machine, the immediate dctection of any break in the thread is essential to avoid jamming of the machine, wastage of thread and an unnecessary slowdown of the winding operation. It is advantageous that a warning signal be provided or the machine be automatically shut down from the moment such a break occurs.

Devices of the prior art for achieving this end result have generally been unnecessarily complicated and expensive and often lack the reliability and life expectancy to be desired.

The device of this invention provides a simple and highly economical means for immediately detecting a break in the thread so as to provide a control signal to a warning indicator and for automatically shutting down the machine. This end result can be achieved by a minor modification to the tensioning gate or arm nonnally utilized in a thread-winding machine and by adding a simple compact detector circuit which can readily be mounted proximate to the tensioning gate. The device of this invention thus readily lends itself to the retrofitting of existing equipment as well as for inclusion in new installations. The'device of this invention further has high reliability and long life expectancy.

It is therefore the principal object of this invention to provide a simple and highly economical device for generating a control signal when there is a break in thread being wound on a winding machine.

Other objects of this invention will become apparent as the description proceeds in connection with the accompanying drawings, of which:

' FIG. 1 is a block diagram illustrating a typical control circuit as utilized in conjunction with the device of the invention and FIG. 2 is a perspective view illustrating one embodiment of the device of the invention.

Referring now to FIG. I, a control circuit as utilized in conjunction with the device of the invention is illustrated. As to be explained more fully in connection with FIG. 2, thread being wound passes through thread gate 11 which tensions the thread; Permanent bar magnet 18,.is attached to thread gate ll. With thread-winding machine30 in normal operation and the thread being properly tensioned in thread gate 11, magnet 18 is positioned far enough from magnetic reed switch 24 so that this switch is not magneticallyv actuated by the magnetic field of the magnet and thus remains in its open position. If,

however, the thread should break, thread gate 11, as to be explained more fully in connection with-FlG. 2, moves by virtue of the tensioning force thereon and thereby positions magnet 18 in close enough proximity to switch 24 to magnetically close the contacts of this switch. The switch arm of switch 24 may be fabricated of any suitable resilient magnetic material of high permeability.

When switch 24 is closed, it connects one side of power source 32 through control device 35 and current limiting resistor 33 to the control gate of electronic switching device 34, thereby actuating this device to provide a current path from power source 32 through control device 35. Control device 35 is thus actuated to provide an appropriate control signal to actuate indicator 37 and to deactuate thread-winding machine 30. Control device 35 may comprise a relay for providing power to indicator 37 and removin'gpower from thread-winding machine 30. Electronic switch 34 has been shown as a bidirectional switch such as, for. example, a commercially available Triac. Such a bidirectional switch of course can be used for maximum efficiency in conjunction with an AC power source. In the event that power source 32 is a direct current source, electronic switch 34 may be a unidirectional device such as a silicon controlled rectifier with which a reset function is provided for turn off.

It is to be noted that the operation of the device can also be implemented with the magnet in close enough proximity to the switch to keep it closed during normal operation with the mugnet moving away to permit the switch to open when the thread breaks. In this instance, of course, the switch would be "actuated when in its open condition.

Referring now to FIG. 2, one embodiment of the device of the invention is illustrated. Thread tension gate ll includes a fixedly mounted gate section 16 and a movably mounted gate section or arm 17, the thread 23 being tensioned between the intenneshing fingers of these two sections. Movable section 17 is mounted for pivotal motion on pivot pin 15, the fingers 17a of this gate section being urged against string 23 by virtue of the action of tensioning spring 21.

Fixedly attached to the end of movable gate section 17 is permanent bar magnet 18. Positioned in the general vicinity of the movable gate section and the bar magnet is thread break detector assembly 19 in which magnetic reed switch 24 is mounted in a position close to magnet 18. Thread break detector 19 has a casing of nonmagnetic material such as plastic, and may additionally include mounted therein the limiting resistor 33 and electronic switch 34 described in connection with FIG. I. H

Should thread 23 break, movable gate 17 no longer being restrained by the thread will be rotatably driven counterclockwise on pivot pin 15 by spring 21, thereby bringing bar magnet 18 in close enough proximity to reed switch 24 so that it magnetically actuated this switch to its closed position. As already explained in connection with FIG. 1, the actuation of the switch produces a control signal which shuts down the thread winding machine and simultaneously may provide a warning indication such as a buzzeror a warning light.

The device of this invention thus provides a simple yet highly effective means for generating a control signal when the thread breaks in a thread-winding machine or the like. The

device lends itself to incorporation with existing thread-tensioning gates, involving but minor modification to such existing equipment.

lclaim:

1. In a thread-winding machine, said thread-winding machine including a tension gate having a fixed portion. a movable ann portion, and means for urging said arm portion so as to tension thread between said movable ann portion and said fixed portion, the improvement comprising;

a detector device for generating a control signal, in the event the thread should break, comprising:

a magnet fixedly attached to said movable gate portion;

a magnetic reed switch mounted in the vicinity of said magnet, said switch being adapted to be actuated when said magnet comes to a predetermined distance therefrom; 7

said movable arm portion being urged when said thread breaks to a position whereby said magnet is brought to said predetermined distance from said reed switch; and

means responsively connected to said reed switch for providing a control signal when said switch is actuated.

2. The device of claim 1 wherein said control means comprises a power source, an electronic switch having a pair of conduction electrodes, one of said electrodes being connected to said power source, a control device connected between the other of said conduction electrodes and said power source, said electronic switch further having a control gate, said reed switch being connected between said control gate and said power source.

3. The device of claim 2 and further including an indicator device responsively connected to said control device.

4. The device of claim 2 wherein said control device is adapted to shut said machine down when said switch is actuated.

5. in combination, a thread tension gate, said tension gate including a fixed portion, a movable arm portion, and means for urging said movable portion toward said fixed portion:

thread tensioned between said fixed and movable portions;

a magnet member fixedly attached to said movable portion;

means responsive to said reed switch for providing a control signal when the thread breaks and the magnet actuates the switch.

6. The device of claim 5 wherein said movable gate is pivotally mounted and rotates about'an axis substantially parallel to the thread as it travel's'through the tension gate.

7. The device of claim 5 and further including indicator means for providing a warningsignal in response to said control signal. 

1. In a thread-winding machine, said thread-winding machine including a tension gate having a fixed portion, a movable arm portion, and means for urging said arm portion so as to tension thread between said movable arm portion and said fixed portion, the improvement comprising; a detector device for generating a control signal, in the event the thread should break, comprising: a magnet fixedly attached to said movable gate portion; a magnEtic reed switch mounted in the vicinity of said magnet, said switch being adapted to be actuated when said magnet comes to a predetermined distance therefrom; said movable arm portion being urged when said thread breaks to a position whereby said magnet is brought to said predetermined distance from said reed switch; and means responsively connected to said reed switch for providing a control signal when said switch is actuated.
 2. The device of claim 1 wherein said control means comprises a power source, an electronic switch having a pair of conduction electrodes, one of said electrodes being connected to said power source, a control device connected between the other of said conduction electrodes and said power source, said electronic switch further having a control gate, said reed switch being connected between said control gate and said power source.
 3. The device of claim 2 and further including an indicator device responsively connected to said control device.
 4. The device of claim 2 wherein said control device is adapted to shut said machine down when said switch is actuated.
 5. In combination, a thread tension gate, said tension gate including a fixed portion, a movable arm portion, and means for urging said movable portion toward said fixed portion: thread tensioned between said fixed and movable portions; a magnet member fixedly attached to said movable portion; magnetic reed switch means positioned in proximity to said magnet member, the distance between said magnet member and said reed switch being too great to provide a sufficient magnetic field to actuate said switch when the thread is being tensioned between said fixed portion and said movable arm portion; said movable arm portion being adapted to move to a position in which said magnet is close enough to said magnetic reed switch to actuate said switch when the thread breaks; and means responsive to said reed switch for providing a control signal when the thread breaks and the magnet actuates the switch.
 6. The device of claim 5 wherein said movable gate is pivotally mounted and rotates about an axis substantially parallel to the thread as it travels through the tension gate.
 7. The device of claim 5 and further including indicator means for providing a warning signal in response to said control signal. 